Genetics of litter size and foetal loss in pigs
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Research partners: Roslin Institute (University of Edinburgh)
Industry partners: BPEX
Duration: November 2007 – October 2010
Female reproductive performance is a critical component of sustainable pig production systems. Increasing the number of viable and productive offspring per reproductive female reduces financial and environmental costs and improves the sustainability of the system. The low heritability of traits such as litter size and pre-natal survival and their expression only in females limit improvement of these traits through traditional selective breeding programmes. However, there is abundant evidence of genetic variation in these traits between pig breeds.
The aims of this project are to identify the components of DNA (QTL – quantitative trait loci) that are closely linked to reproductive traits, including litter size and embryo survival and to identify and characterize these influential genes.
The genetic mapping part of this project is complete and the functional aspect is underway. Samples of reproductive tissues from the French population of Meishan and Large White pigs were collected during the year to enable a breed comparison study to be carried out; analysis of the results is ongoing.
The genetic markers identified to date do not have an immediate application in Marker Assisted Selection for increased litter size as the relationship between the marker genes and genes at the QTL with effects on litter size, embryo survival etc. would need to be determined in each population of interest. In subsequent stages of this project there may be opportunities to discover markers in close linkage disequilibrium with the QTL and which would be predictive in most populations.